OlderThanMe Posted July 12, 2006 Share Posted July 12, 2006 I have been in the search of some cheap sidedraft webbers or something similar. The fact is that it is not cheap to do. I was wondering if anyone knows if anyone has put tripple SUs on an L6. I searched and did not find anything about it. Some of the old Jag D types that did not have webbers had triple SUs. Since you can get an SU much cheaper than a twin barrel side draft I thought it would be a good conversion. I have the ability to have the runners made so that is not a problem. I am also getting pretty good at tuning SUs to run good so I don't want to start over with a different carburetor. I think that three big mouth rebello SUs would provide more than enough air for a ~270 horsepower 3.0 or the like. I already have a pair of SUs that I am using and would only need one more. A lot of guys have the SUs but want more but don't want to spend near two grand for a 50% increase in flow. If there would be an intrest I could buy two full sets of carbs and build two triple SU sets as not to have an extra carburetor sitting around. The tripples would all have equal length runners unlike the stock SU lengths which aren't the same but are close. I heard about someone that put tripple SUs on their L6 but I can't find the web page. ideas, comments questions? Thanks OTM Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 12, 2006 Share Posted July 12, 2006 Search on classiczcars.com. They just had a thread on the subject maybe a month ago complete with pictures, etc. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 12, 2006 Author Share Posted July 12, 2006 ok. thanks a lot! Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 12, 2006 Author Share Posted July 12, 2006 good greif...those guys at classiczcars.com can make drama from nothing! Just read the thread that you mentioned and I am going to read some of the older threads over there. Looks as long as you use a balance tube everyhthing should work. Quote Link to comment Share on other sites More sharing options...
veritech-z Posted July 12, 2006 Share Posted July 12, 2006 what are you going to use for a throttle linkage? It might be better to try and find the larger 2" jaguar carbs and just stick with two. http://cgi.ebay.com/ebaymotors/Jaguar-XKE-S1-SU-Triple-Carbs-with-4-2-Intake-Nice_W0QQitemZ150008465151QQihZ005QQcategoryZ6763QQssPageNameZWDVWQQrdZ1QQcmdZViewItem http://cgi.ebay.com/ebaymotors/CARBURETORS-Jaguar-XJ-12-Cylinder-2-SU-Side-draft_W0QQitemZ230005643109QQihZ013QQcategoryZ33550QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 12, 2006 Author Share Posted July 12, 2006 here is an L6 tripple SU intake. looks fairly simple. http://www.classiczcars.com/forums/attachment.php?attachmentid=839&d=1031206053 a throttle linkage could be built. I would not need to worry about using a stock air cleaner like the guys at classiczcars.com were wanting to use. Why would you want to use a restrictive stock intake with triple SUs? I was thinking making all new aluminium runners and a cold air intake since I am going to be using a belly pan and won't get that much cool airflow past the carbies. I can have the shop at my welding school build me one since I am graduated now. oh...I can TIG weld all day long so that is not a problem. I just need a TIG-AC welder and I would be set. I just need $2000 for a nice Synchrowave 200. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 12, 2006 Share Posted July 12, 2006 I just don't get why anyone would bother with the SU's. It's not that it "doesn't work". Clearly a car will fire up and run with triple SU's. I don't doubt for a second that triple SU's would have better top end than dual SU's. But, I don't think anybody disputes the idea that triple sidedrafts with 6 chokes work better than triple SU's. So why bother with all the labor to get an inferior end result? If you want something custom and you don't want to shell out for Mikunis or webers, you might do like 1_fast_z and have some dual throttle bodies put onto a triple-ish manifold and run MS. There are enough cars out there now with dual TBs that you should be able to source the parts cheaply and the end result would be better. Good luck whatever you decide. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 12, 2006 Author Share Posted July 12, 2006 all true points. I am just a poor college student that has a bit of time on my hands. I figure I could do it for maybe $100 of aluminium plus the extra carb. I am slowly begining to like FI because you can tune the poo out of it to be very precise. I may just keet the pair until I can afford FI stuff after my motor rebuild. I want to just build a good motor that will last for a long time and will make good power. A 3.0 sounds like a good option and pretty reliable for the amount of power and money. I don't want to build something that won't be cost-effective. I hate throwing money at a project that ends up not working or taking too much time to get right. I am thinking that if I build it myself I can have a 3.0 *longblock* at 250-270 horsepower for $3500. I have a friend that works at a machine shop so he could probably help out or at least point me in the way of a good machine shop in the area. Thanks for the opinion Jmortenson! OTM Quote Link to comment Share on other sites More sharing options...
Forrest Posted July 12, 2006 Share Posted July 12, 2006 Building a 3.0L and getting 250hp out of it is going to cost a heck of a lot more than just getting a junkyard L28ET and going through it. Actually it probably costs more than swapping in an SBC. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 12, 2006 Author Share Posted July 12, 2006 yeah I know...looking through different threads and articles it looks like it will cost about 3 grand with labor and parts. I don't want a turbo motor. At least not right now. If I get into turbo stuff now I would have to do the holset and a nice BOV...etc. I would rather learn how to rebuild an NA motor and gain power while I am at it. I don't even know if a 3.0 can be made from a L26. If someone has a free or cheap L28 shortblock that would be nice...I doubt that is going to happen though. I am just a litttle upset that I had my engine running near perfect a week ago and then 2 days later I cranked it and it started knocking and getting bad fast. It got much worse in about 5-6 minutes of running which makes me think it is an oiler. I have done very little work on my engine other than some ignition stuff but that is not much. I ordered the book "how to rebuild and modify your datsun engine" from borders and it will be here this weekend. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 13, 2006 Share Posted July 13, 2006 The timing chain on the L6's get oiled through the chain tensioner. On the L4's they use an oiler, but it doesn't really look like what you show in your sig. No idea how that piece in the picture would have been used on an L6. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 13, 2006 Author Share Posted July 13, 2006 well this is why they call the 260Z the red-headed stepchild... Quote Link to comment Share on other sites More sharing options...
JaysZ Posted July 13, 2006 Share Posted July 13, 2006 olderthanme, where are you located? i have a shortblock available. depending on where you are or how much you are willing to spend on shipping/crating... i could sell you mine. 260 block, E88 head. runs very strong. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 13, 2006 Author Share Posted July 13, 2006 see. My 2.6 shortblock is ok. I want to build a 3.0 but I don't know if that is possible to bore out my block that far. It is proven that the 280 block can go to 3.2 but nobody knows if a 2.6 can go to just 3.0. Quote Link to comment Share on other sites More sharing options...
Sven Posted July 19, 2006 Share Posted July 19, 2006 I too was curious recently about the triple SU question, so I picked up a working Jag setup (complete) for a song to check out. I already have Mikunis, but can examine them closely and still turn around and sell later. It helps that the one ad posted above sold for about 6X what I paid...I keep telling myself it's an investment I'll post detailed pics and some measurements soon in a week or so. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 19, 2006 Share Posted July 19, 2006 Not sure what all the fuss is regarding triple SUs. L24 engines built to SCCA EP specs make 250 to 265 hp on slightly modified OEM dual SUs. As posted here many, many times before, the intake side of the L6 engine is not the restriction. BTW... I have a set of 50mm (2") SUs that I would be willing to sell for $450. I had plans for them but the plans changed. Quote Link to comment Share on other sites More sharing options...
Sven Posted October 15, 2006 Share Posted October 15, 2006 Okay, as promised long ago, I finally got around to taking some pics of my Jag triple SU setup. This should give some a better idea of the arrangement of three SU carbs . Remember, these are the 2"/50mm HD8 SU, so they are different than the Hitachi ones. (Side note: I'm looking to unload these soon, if anyone has an XKE or XJ that needs carbs PM me.) For some reason this topic really gets people's hackles up, and I'm not sure why. I think the potential is great. Use the often discarded factory Z SU's (far less $ than anything else, sometimes free), jet them down or use the roadster or 510 smaller bore carbs, and get similar performance with potentially better drivability and mileage. If the factory round dome SU's are intended for good stock performance on a L24, why wouldn't three be in the ballpark for a seriously modifed L28 or stroker pushing over 200 rwhp? The twin SU manifolds for the 510 could be used as a starting point to weld something up (1 carb to 2 cyl vice 1 carb to 3cyl). If you look at the second pic above you can see Jaguar's common plenum above the individual runners, eliminating any firing order/intake pulse issues. I think you would want to duplicate that, or at least run large diameter tubing linking the runners together, like a fat fuel rail. That is something I feel the guy on Classiczcars did not do adequately, it only looks like 1/2" tubing. I am very surprised no aftermarket manufacturer tooled up in the seventies to make such a manifold. How many SU's got thrown away? I think it may have something to do with the percieved "sexiness" of Webers and Mikunis, and America's love affair with the 4 barrel. I think the three SU's in a row look pretty damn cool polished up. An interesting thing I noticed about the inlet plenum/airbox can be seen in the pic below. The carb inlets are dropped off the main header, and have little flow directing vanes before the throats. I assume this is to minimize turbulence at the carb entry, which is a common issue on a ram-air box with carbs. I like it. (here you can see the linkage arrangement) The Jag guys I've spoken to feel very strongly about the performance, drivability, and ease/lack of continual tuning with the triple SU's vice Webers. A GT winning race team in the early 80's did much dyno testing and concluded they out performed Webers on the Jaguar l6. I'm sure that may not be true in every engine's case, but they followed their testing, used SU's in competition even though they had the option to use other carbs, and ending up winning a championship. I'm in no hurry to tear off my Mikuni's, but I like this idea alot. I will fart around with it in my spare time, and hopefully end up with something I can test back to back against the carbs on my car. Call it a mental engineering exercise, or a waste of time. My neighbor is an alum welding genius, I'd hate to let that go to waste... Quote Link to comment Share on other sites More sharing options...
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